Plants Are So Awesome, Their Roots Can Sense Light Underground

The stem acts like a 'fiber optic cable,' piping light down to parts that are buried underground. Internet of Plants, here we come.
November 1, 2016, 6:22pm

Plants are more hi-tech than you thought: a new study published today in Science Signaling reveals that certain plant stems act like fiber optic cables to deliver light from the leaves to the roots so they can grow. This is a cool finding because it shows parts of the plant that never actually see the sky are still sensitive to light.

The study, run by more than a dozen researchers from institutions in South Korea and Germany, hopes the results can be used to determine the best lighting conditions for growing some plants.

Having a better understanding of how plants use light means we can grow various plants in greenhouses more effectively. And if you want year-round tomatoes, that makes a difference.

Light isn't as simple as illumination when it comes to plants. It's a source of energy, and a signal that regulates most functions within the plant.

Researchers studied the mustard plant, the Arabidopsis thaliana, using plants whose roots were completely shielded from the light. They found that light travels down through the stem to activate photoreceptors in the roots, which stimulates growth, and keeps the plant growing vertically.

While researchers knew roots also had photoreceptors—the parts of the plant that soak up light—they weren't sure whether those photoreceptors responded directly to light above ground, and how. The results that plants actively pump light down to the roots answers that question.

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